Floor panels for use in floating floor systems typically comprise a top layer and a bottom layer adhered together in an offset relationship such that a substantially L-shaped marginal end portion of a top surface of the bottom layer and a substantially L-shaped marginal end portion of a bottom surface of the top layer are exposed. The top layer typically comprises at least one mix layer, a print film, a wear layer, and a top coat. The bottom layer typically comprises at least one mix layer. The bottom layer has a thickness about equal to or greater than the top layer. A ratio of a thickness of the top layer to a thickness of the bottom layer is typically in the range of about 2 or less. For example, the SURFACE SOURCE product sold by Lowe's Home Centers, Inc. has a top layer with a thickness of about 64 mils (about 1.63 millimeters), and a bottom layer with a thickness of about 61 mils (about 1.55 millimeters). Thus, the ratio of the thickness of the top layer to the bottom layer is about 1.05 (64 mils/61 mils=1.05).
In order to assemble the floating floor system, at least one of the marginal end portions of each of the floor panels is provided with an adhesive. The marginal end portion provided with the adhesive is engaged with the marginal end portion of an adjacent floor panel to form the floating floor system. The floor panels may be formed, for example, such that when the floating floor system is assembled on a sub-floor ends of the top layers of the adjacent floor panels substantially abut, while ends of the bottom layers of the adjacent floor panels are spaced apart a desired distance so that a gap is formed there between. Alternatively, the floor panels may be formed, for example, such that when the floating floor system is assembled on the sub-floor the ends of the top layers of the adjacent floor panels substantially abut and the ends of the bottom layers of the adjacent floor panels substantially abut.
Because the thickness of the bottom layer is significantly large (about 98 mils (about 2.5 millimeters)), when the floor panels are assembled such that a gap is formed between the ends of the bottom layers of the adjacent floor panels, the gap can telescope through the floor panels thereby significantly altering the aesthetic and structural characteristics of the top layer. For example, the gaps may cause deformation at a top surface of the top layer. Alternatively, when the floor panels are assembled such that the ends of the bottom layers of the adjacent floor panels substantially abut, unwanted gaps or overlapping can occur between the ends of the top layers due to deviations in the size of the marginal end portions and/or errors occurring during installation. These unwanted gaps or overlaps can additionally telescope through the floor panel thereby also significantly altering the aesthetic and structural characteristics of the top layer.
Additionally, the marginal end portions of the top layer of a first row of the floor panels, which are typically positioned adjacent a wall, remain unsupported when the floating floor system is assembled, because the marginal end portions of the top layer of the first row of the floor panels will not engage with an adjacent floor panel. Thus, because the thickness of the bottom layer is significantly large, the gap occurring between the sub-floor and the marginal end portion of the top layer will also negatively impact the aesthetic and structural characteristics of the top layer. For example, deformation at the top surface of the top layer can occur. Also, because the bottom layer and the top layer comprise mix layers, which contain fillers, the bottom layer and the top layer are prone to absorb moisture thereby further affecting the aesthetic and structural characteristics of the floor panels. This is particularly problematic, since the bottom layer is installed directly on a sub-floor.
Still further, because the bottom layer has a thickness greater than the top layer, when the floor panels are stacked, for example, during shipping, a space exists between the marginal end portions of the top layer of the adjacent flooring panels equal to the thickness of the bottom layer. Thus, during shipping, the unsupported marginal end portions of the top layer are prone to bend and/or curl an amount equal to the thickness of the bottom layer. Because of the structural characteristics of the top layer and the “vinyl memory” of the panels, these bends and/or curls remain in the marginal end portions of the top layer during installation and can thereby significantly alter the aesthetic and structural characteristics of the floor panel. For example, deformation can occur at the top surface of the top layer and/or the bond strength between the marginal end portions of the adjacent floor panels could be negatively affected.
In an attempt to provide better visuals for the flooring system, co-pending U.S. patent application Ser. No. 12/412,419 discloses a floor panel and a floating floor system incorporating the floor panel include a floor panel having a top layer and a bottom layer. The top layer has a top surface and a bottom surface. The top surface has a visible decorative pattern. The bottom layer has a top surface and a bottom surface. The top surface of the bottom layer is adhered to the bottom surface of the top layer such that the bottom layer is offset from the top layer in a direction of length and width and a marginal end portion of the top surface of the bottom layer and a marginal end portion of the bottom surface of the top layer is exposed. At least one of the marginal end portions has an adhesive, and a ratio of a thickness of the top layer to a thickness of the bottom layer is about 5 or greater. Because the thickness of the bottom layer of the floor panels is significantly less than the thickness of the top layer, when the adjacent floor panels are engaged, any unwanted gaps or overlapping that may occur between the first and second ends of the bottom layers of the adjacent floor panels due to deviations in the size of the marginal end portions and/or errors occurring during installation will minimize the aesthetic and/or structural characteristics of the top layer. However, this solution requires a bottom layer that almost completely covers a bottom side of the top layer with a bottom layer of rigid vinyl PVC film or some vinyl composite material of certain thickness to create the ship lap structure. This demands a significant amount of back material as well as adhesive to attach the bottom layer to the top layer. In addition, most of the liner use on the bottom layer must be stripped off and thrown away during the assembly process. The assembly of such large bottom layer onto the top layer is difficult and labor intensive and the use of the rigid bottom layer, which is harder than the top layer itself, may cause the offset lines from the bottom layer to transfer visual imprint defects to the top layer.
In view of the foregoing, there still remains a need to develop a floor panel that overcomes the above-described problems. Additionally, there still remains a need to simplify the manufacturing process for such floor panels and reduce the expense associated therewith.